Synthesis of highly substituted dienes via silaboration and crosscouplingreactions

A synthetic approach to highly substituted dienes has been investigated. In a four step synthesis, a wide range of molecules can be formed: Sonogashira coupling between an alkyne and a bromoalkene, silaboration of the newly formed enyne, Suzuki‐Miyaura coupling to exchange the boronic ester moiety, and silver(I) oxide activated crosscoupling to replace the silicon atom. The majority of final compounds are afforded in moderate to good yields (20‐55% over 4 steps). In some cases, the last step where the silyl moiety is exchanged to an aromatic ring has caused some problems: isomerization and lower yields